This invention relates to needles and more particularly to felting needles having an improved fiber protecting barb construction.
Felting needles are in use in the needle punching process for compacting a fiber web into a backing material. These needles have fiber engaging barbs on the needle edges that act to compact the fibers by forceably orienting them into a dense web. The quality of a highly compacted needle product is highly dependent upon the amount of fiber and backing distortion produced during the process. It is therefore important that the fibers and the backing be protected so that distortion is minimized. This is especially critical for brittle fibers and those that have low tensile strength. The barb of the needle is the proportion that grips the fibers to interlace and orient them into a compact web. However, with the barb constructions of the prior art, as the degree of fiber gripping increased, so did the degree of distortion. Some examples of prior art felting needle barb constructions are illustrated in U.S. Pat. Nos. 2,857,650; 3,641,638; 3,983,611; and 4,030,170. The needle disclosed in the latter patent is free of the so called bard "kick-up" i.e., the trailing tip of the barb does not protrude above the edge of the blade.